Alarm apparatus.



' W. H. DANA 6L T. FABRODERICK.

ALARM APPARATUS.

APPLICATION FILED MAY 25. 1915.

1,172,199.t Patented Feb.`15,1916.

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mm H. DANA AND THOHAS F. BRODERICK, 0F LAWRENCE, MASSAHUSETTS.

Y ALARM ArrAnATUs.

Specification of Letters Patent.

Patented Een. 15, 1916.

Application mea :my z5, 1915.- l serial no. 30,386.

To all whom it may concern: l

Be it known that We, WILLIAM H. DANA and THOMAS F. BRODERICK, citizens of the United States of America, residing at Lawrence, in the county ofEssex and State of Massachusetts, have invented new and'useful Improvements in Alarm Afpparatus, of which the following is a speci cation.

This invention relates to improvements in alarm apparatus and has vparticular application to an automatic alarm for automatic sprinkler systems-of the dry type.

In carrying out the present invention, it is our purpose to provide an alarm apparatus of the class described whereby an alarm will be sounded in the event of the escapeof air from the dry pipe of the sprinkler'system so that the controlling valve may be actuated to ,cut off position to prevent the fiow of water the system and determine the cause of the.

pressure reduction previous to closingv the controlling valve.

A. further object of'our invention is the provision of an alarm apparatus of the type set forth whereby the alarm will be sounded in the event of Water entering the dry pipe system, thereby notifying the attendant of the condition of the system.

With the above and other objects in view, the invention consists in the construction, combination and arrangement of parts hereinafter set forth in and falling within the scope of the claim.

Inv the accompanying drawing, Figure 1 is a diagrammatic view of an alarm apparatus constructed in accordance with the present invention, parts being shown in section. Fig. 2 is a top plan view of the pressure controlled mechanism.V

' Referring now to the drawing in detail, 1 designates one end portion of a dry pipe of an automatic sprinkler system and projecting upwardly from the end of the dry Ypipe and connected thereto by means of an appropriate form of elbovl is a vertical nipple 2.

3 designates a spherical casing comprising a lower section 4 and an upper section 5, the confronting edges of the sections 4 and 5 being formed with outwardly projecting circular ianges 6 provided with lalining bolt holes to receive securing bolts 7 whereby the sections 4 and 5- are held in casing formation. The lower section 4 of the casing 3 is,

formed centrally with a threaded opening 8 designed to receive the upper end of the nipple 2 so that the casing may be supported upon the nipple and the upper section 5 of the casmg is formed with an opening 9 alinmg axially with the opening 8 in the bottom sectlon. v-

Clamped between the confronting faces of the flanges 6 is the peripheral edge of a d1aphragm 10 and secured to the diaphragm 10 at the centerthereof is the lower end of a vertical stem 11", such stem being passed through the opening 9jin the section 5 of the casing. Passed through the flanges 6 on the .sections 4 and 5 and suitably secured thereto is the lower end of a vertical post 12 havlng the upper extremity thereof formed with a yoke 13 ahning with a collar 14 formed on the upper end of the stem 11. Also secured tothe flanges 6 at a point diametrically opposite the post 12 is the lower end of a vertical post 15. Formed on the vertical post 15 and projecting laterally therefrom are lugs 16, 16 spaced apart vertically and each formed adjacent to the. outer end thereof With l an opening carrying an insulating bushlng 17. Threaded through the bushings '17 are screws 18 and arranged between the lugs 16, 16 and disposed at one side of the vertical post 15 is a horizontal lever 19 having one end thereof pivoted within the yoke 13 on the upper end of the stem 12. Slidably mounted upon the remaining end portion of the arm 19 is a weight 20 capable of longitudinal movement along the arm and equipped with a set screw 21 whereby the weight may be held in the desired adjusted position. The screws 18, A18 are electrically connected to each other by means of a vertical wire ,22, such wire having the extremities thereof bent at right angles t0 the main body-portion ofthe wire as'at '23 and engaging the outer surfaces of the respective lugs 16 and formed with openings alining with the openings in the bushings to accommodate the screws 18. Connected .with one of the screws 18 is one terminal of an electric circuit 24, such circuit'including a suitable source of electrical energy Aas a battery 25-and an alarm 26, the alarm being here shown as a bell. The remaining terminal of the circuit 24 is grounded as at 27. In the present instance, a yoke -28 has the central portion thereof formed with an opening to receive the stem 11 and the end portions bolted to the flanges 6, such yoke acting to insure the proper movement of the stem 11.

lin practice, as long as the air pressure in the dry pipe 1 is maintained, the diaphragm 10 is held in normal position and the lever 19 held at a point approximately centrally of the -distance between the screws 18, thereby holding the circuit 24s open. When, however, the pressure in the dry: pipe is lowered and? the diaphragm 10 relieved, the weight 20 swings the lever 19 downwardly into engagementwith the lower contact screw 18,

thereby closing the circuit 23 and soundingv the signal 26. lin the event of water enter` ing the dry pipe, the' pressure on the diaphragm is increased and in the upward movement of the diaphragm under the increased pressure thereof the lever A19 engages the upper lcontact screw 18, thereby closingthealarm circuit. l Y

adapted to lower the latter when the dia.

phragrn is relieved of pressure, anV electric circuit under the control of said lever, and means associated with the collar on said post for limiting the swinging movement of said lever.

ln testimony whereof we affix our signatures in presence of two witnesses.

l/VllLLlAM H. DANA. THOMAS F. BRODERCK. Witnesses:

A. ROY WYNOTT, ll/'IJLLIAM4 C. MUNRO. 

